You really should warn players about using the simulator. A vague description like the one in the officers "level 1 will add several defenses, level 2 supports big ships..." is nothing. You should be more specific. Especially for new players who learn to trust the simulator from early battles, loose fleets because of it without a warning. It is a waste of the time and the effort they have put into game, so they get angry and leave it:(
Instead, simulator should be a lot more specific about what it can do. When called with a simulation that includes small and large shields, it should pop up a window saying that "small and large shields were detected. Results will not be accurate , unless officer l 1 is hired". Giving the wrong result without a warning, is a gross error:(